The Imaging, Methodology and Statistics (IMS) core will integrate and coordinate efficient and consistent utilization of neuroimaging and statistics resources across the 3 program projects by providing standard methods and staff support that will be readily accessible to investigators. The IMS core will serve as a technical core for data acquisition, processing, and evaluation and for the development of novel analyses and software. In this manner, the IMS core will be an integral component of each project and support research that begins to address issues of the general utility, sensitivity, and specificity of PIB in the PET imaging detection of fibrillar amyloid in the brain of controls and in patients with mild cognitive impairment and Alzheimer's disease (AD) and also in Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB). The central aims of the IMS cores are to: 1) apply quantitative neuroimaging methods to measure amyloid binding, cerebral metabolic rate, and hippocampal/brain morphometry across the AD disease spectrum;2) compare amyloid binding, metabolic rate, and brain structure cross-sectionally across the AD disease spectrum and in PDD and DLB;3) determine temporal and spatial characteristics of the neuroimaging measures across time and relative to cognitive performance in the same subject groups. The program project research described in this application represents the first fully quantitative clinical evaluation of this kind performed on any amyloid imaging tracer. The core will perform a careful evaluation of the utility of PIB PET across the AD disease spectrum and in PDD and DLB by performing analyses that examine group identification (e.g., statistical classification), by applying statistical modeling to explore relationships among neuroimaging measures and measures of disease severity (e.g., MMSE) and questions involving "dementia conversion". The IMS core activities will further validate PIB PET imaging for clinical application on a cross-sectional and longitudinal basis.